Incorporating spatial analysis of habitat into spiny lobster (Panulirus argus) stock assessment at Alacranes reef, Yucatan, México

In this paper, spatial analysis of submerged habitats was incorporated into spiny lobster (Panulirus argus) stock assessment at Alacranes reef, Yucatan, México. Two sources of information were used: a thematic map of submerged habitats obtained using a Landsat TM satellite image and “geo-referenced” field data for lobster catches obtained during July 1998 and February 1999. Geographical information systems (GIS) tools were used as the major basis for displaying, analysing and relating lobster catches data and the thematic map information. Estimations of lobster abundance, density and biomass per habitat class and for the whole reef, at the beginning and end of the fishing season, were obtained. Utilizing Monte Carlo modelling, uncertainty was incorporated to estimations of transects initial and final position, appreciation of area and probability to detect lobsters. Results were compared against commercial catches reported for the previous year. The distribution of fishing effort is also described.